just a minor correction to the sample solution:
It's not necessary to attach the offset-list to the Tunnel 0 interface because split horizon is still enabled from a previous task.
At the top on "Note" section, it states to load the initial configuration files for the section.... which states previous
task should be resetted. I agree with you if previous task is still enabled.
Hi,want to know why we cannot use the below offset list ( GigabitEthernet1.146 instead of Tunnel 0 ) if we want to route the traffic over VLAN 146 ?
offset-list 1 in 3 GigabitEthernet1.13
offset-list 1 in 3 GigabitEthernet1.146 ===>
Although aware that did not get the desired result ( traffic still being routed over R1->R3 even though Gig1.146 is up as seen below)
R1#sh ip int b | i 1.146
GigabitEthernet1.146 126.96.36.199 YES NVRAM up up
Type escape sequence to abort.
Tracing the route to 188.8.131.52
VRF info: (vrf in name/id, vrf out name/id)
1 184.108.40.206 2 msec * 1 msec
R1#sh ip route 220.127.116.11
Routing entry for 18.104.22.168/32
Known via "rip", distance 120, metric 4
Redistributing via rip
Last update from 22.214.171.124 on GigabitEthernet1.13, 00:00:04 ago
Routing Descriptor Blocks:
* 126.96.36.199, from 188.8.131.52, 00:00:04 ago, via GigabitEthernet1.13
Route metric is 4, traffic share count is 1
If you set your Offset-list in from G1.146 you as you have above it would incriment the hop count of the route from that interface by 3. This would not give the desired result of chosing the VLAN 146 route above the G1.13 and tunnel 0 connection.
Review the task:
If you apply the offsets of
offset-list 1 in 3 GigabitEthernet1.146
This would make the hop count for the g1.146 of 6 for the 184.108.40.206/32 route and 4 of the g1.13 link.
Though if there were no other offset lists affecting the routes the router should choose the tunnel to forward the traffic to R3's loopback, since it should have a hop count of 2. If you did not modify it in any way.